Flexible shaft coupling



Nov. 12, w40. J, M BOWMN 2,221,668

FLEXIBLE SHAFT COUPLING yFiled June-2.9,' 1937 Patented Nov. '12, 19.40

UNITED STATES FLEXIBLE SHAFT ooUPLiNG Joh M. Bowman, vPhila mesneassignments, t Inc., Carson City, Ne vada delphia, Pa., assgnorfby oPennsylvania Patents, v., .a corporation 'of Ne- Application June 9,1937, serial 147,324

This invention relates'to a n ovel method of terminating a, flexibleshaft conduit and to a novel terminal structure provided by such method.`Although th/e invention is Yapplicable to flexible shaft conduits usedfor various purposes, it is particularly directed to those vemployed inconnection with vehicle radio receivers, such as the automobile radioreceivers now in general use.

As Well known in the art, flexible shafts are used to control theadjustable elements -of an automobile vradio receiver, such as thetuning and volume control elements, from-a point remotely located withrespect to the receiving set.

` The set is usually controlled by means of a control device mounted onthe instrument panel of the automobile, andthe flexible shafts extendbe- .tween the said controldevice and the radio set. The conduit forsuchv a flexible shaft comprises a flexible metal tube' formed ofspirally-Wound strip material, and a loom covering on the said tube. Therotatable exible shaft extends through the exible tube. Considerabledifliculty has been encountered in the past in providing a. suitableterminating structure for such a conduit v in order to anchor the endsof the conduit firmly the end of the conduit and the .assembled elementsare crimped to interlock them together. Moreover, the flexible metaltube forming a part of the conduit is held in Afirm engagement with -themetal terminal so that when the terminal is grounded by virtue of itsmechanical attachment to thehousing of either the radio set or thecontrol device, the flexible tube is likewise grounded.

The invention may be more clearly understood 40 by reference to theaccom which Fig. 1 is a perspective View of a. cap-like terminal whichmay be employed according to the invention; and f Figs. 2 to 4illustrate successive steps in the method of forming the terminalstructure. Referring to Figs. 1 to 4, in accordance with one embodimentof the invention, a terminal in the form of a metallic cap having'theshape, shown 'in Figs. 1 and 2 may be employed. This terminal 'has ahead portion I witli an aperture 2 at the center thereof, and acylindrical wall 3, the ,end of which is fiared 'outward as shown at 4.The ter-V 55 minal may be formed from. sheet metal inv ac'- V2 Claims.(o1. 28s-72).

panying drawing, in

cordance with` any of the l: working such material. y

The exible shaft conduit Vabove mentioned is shown in Figs. 2 to l andcomprises the fiexible tube-5 formed of spirally-wound flat-metallic'strip 5 material and a loom covering 6 over the said tube.

As stated above, the exlble control shaft extends through the conduitduring use of the same.

In accordance with'the present invention,the cap-like material is placedover an end of the conduit as shown in Fig. 2 and the end portion of theconduit, to'getherwith the terminalthereon,

is placed in a two-part hollow die member l` having the form shownclearly in Fig. 2. It will be noted that this die member has an annularshoul- 15 der'8, a conical-surface 9 and another annular l shoulderIIJ;` The member is also preferably provided with corrugations Illa toenhance the frictional gripping of the conduit. The initial positioningof the conduit and terminal in die mem- 20 ber 'I is as shown-in Fig. 2.Following the positioning-of 'the assembled parts in 'the die member 1,a complementary` die member II having a pointed end is brought into' theposition shown in Fig. 2 with its pointed end seated in theopening 25 2ofthe terminal. 'Ifhe member II has a cylindrical portion I2 of suchdiameter that it is adapted to slide snugly within the Iiexible tube 5.The die member II also has an annular shoulder I 3, and an arcuateannular surface I4 between the 30 shoulder I3 and the cylindricalportion I5. The lattercylindrical portion is adapted to seat snugly Ywithin the complementary end portion I5aof the die member l. i Asthe diemember II is moved toward the`35 right from the position shown in Fig.2, the con-- duit and the' terminal are held frictionally by the diemember 1, and the pointed end enlarges the opening in the terminalanddeforms the head of the terminal by pressing it inward. When thesurface I4 of die member I I engages the inner wall of the vterminal itexerts longitudinal-pressure on the conduit and causes the conduit andthe terminal to slide within the die member 'I tothe position of Fig. 3.During suchmovement, the ared end 4 is crimped inward bythe surface 9and nally rests against the shoulder 8, while the opposite flared end ofthe terminal comes to rest against the shoulder I0, as shown in Fig. 3.The conduit` and terminal arethen held firmly by thedie member 1 whilethe die member I I exerts further longitudinal pressure. The surface ilAof die member 'Ig presses the outer part of the terminal against theloom6, while the shoulderv I3 of die,v

nown methods l of member .II crimps the tube 5, as shown -at I6, and

the surface I4 presses the inner part of the terminal firmly against theinner surface of tube 5. The end portions of the tube 5 and the loom 6are flared and compressed between the inner and outer parts of theterminal.

When the die member I I is removed, the resilience of the'tube 5 causesthe deformed end thereof to take the form shown in Fig. 4. The parts arethus firmly attached to one another and are interlocked with respect toone another and, at the same time, the metal terminal is in snugengagement with vthe end of the deformed end of tube -5. The flexibleshaft conduit thus terminated may be attached to the metallic radio sethousing or to the metallic housing of the control device above mentionedin any suitable manner, for example by means of a collar adapted toengage the ared end or flange of the terminal and which may be securedto either one of the housings. This, the end of the flexible shaftconduit may be firmly anchored and, at the same time, the metallic tube5 may be eiiciently grounded.

It `will be understood that various other embodiments of the inventionare possible. The invention contemplates broadly the die-forming of aterminal and an associated end of a flexible shaft conduit, so as topress the elements into firm engagement and to crimp -them to interlockthem together.v It will beapparent, therefore, that the invention is notlimited yto the specific forms herein illustrated and described. y

I claim:

1. A terminal structure for a flexible condui including a flexible metaltube and a loom covering thereon, said structure comprising a stampedmetal terminal member tted onto an end of said being deformed or crimpedinwardly to tightlyengage the loom covering, and the end of thecomposite structure being flared outwardly, whereby said terminal memberand said conduit are interlocked with one another against longitudinalrelative movement.

2. A terminal structure for a flexible conduit including a flexibleresilient metal tube and a covering thereon, said structure comprising astamped metal terminal member fitted onto an end of said conduit, saidmember having inner and outer concentric parts connected together by anannular connecting portion extending about and covering the edge of theconduit end, the inner part of said member engaging the inner wall ofsaid tube at the end thereof, the outer part of said member embracingsaid covering over a substantial end area thereof and. being deformed orcrimped inwardly to tightly engage the covering, and the end of thecomposite structure being flared outwardly, the diameter of the flaredend beinggreate than the diameter of the inwardly crimped portion ofsaid outer part, wherebysaid terminal member and said conduit areinterlocked with one another against longitudinal relative movement.

JQHN M.) BOWMAN.

